Heel strap



FIG. 1 is a left side elevational view of a heel strap in its closed form, as worn by a person, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view similar to FIG. 1;

FIG. 4 is a top plan view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a bottom plan view thereof;

FIG. 8 is a rear plan view of the heel strap in its open condition, and,

FIG. 9 is a front plan view thereof. 

The ornamental design for a heel strap, as shown and described. 